JPS62106150A - Transmission structure of agricultural vehicle - Google Patents

Abstract

PURPOSE:To supporess shock upon changing of speed, by providing an actuator from which oil is discharged when a control valve is in a forward position, while the oil is supplied from the control valve to the actuator in parallel to a reverse hydraulic clutch when the control valve is in a reverse position. CONSTITUTION:A pressurized oil is supplied from a pump 22 to a main control valve 23 for supplying the oil to a hydraulic clutch 20 in a main transmission. When the main control valve 23 is in a forward position, the oil in a single acting hydraulic cylinder 30 is discharged to engage a reaping clutch 14. When the main control valve 23 is selected to a reverse position, the pressurized oil is also supplied to the hydraulic cylinder 30 to disengage the reaping clutch 14 and simultaneously engage a reverse clutch 20d. Accordingly, the selection from the forward postion to the reverse position may be smoothly carried out with a reduced shock.

Description

[Detailed Description of the Invention] [Field of Industrial Application] The present invention relates to a hydraulically operated hydraulic clutch that performs gear shifting by selectively operating a plurality of hydraulic clutches for gear shifting by supplying pressure oil from a control valve. The present invention relates to a speed change operation structure for an agricultural vehicle equipped with a traveling speed change device.

[Conventional technology]

An example of the pressure oil supply path in the above-mentioned speed change operation structure is disclosed in Japanese Utility Model Application No. 59-188341, which connects an accumulator to the primary side of the control valve to move the control valve from the neutral position to the other position. The structure is designed to prevent the operating pressure of the pressure oil supplied to each hydraulic clutch from rising suddenly when the gear is shifted to the position shown in Fig. 1, thereby suppressing the shock at the time of starting. I had a problem like this.

[Problem that the invention seeks to solve]

The accumulator functions only when supplying pressure oil to any hydraulic clutch from a neutral state where no operating pressure is generated in any hydraulic clutch, and when pressure oil is supplied to a certain hydraulic clutch. If the supply destination of pressure oil is changed from the current state to another hydraulic clutch, it can be said that the pressure accumulation effect hardly works.

Therefore, when shifting from one forward gear position to another forward gear position, acceleration and deceleration are performed while moving forward, so there is less shock when the operating hydraulic clutch changes, but the forward gear position When the gear is changed rapidly from the gear position to the reverse gear position, the shock is quite large because the accumulator hardly works.

This has been a particular problem for agricultural vehicles that frequently move back and forth to work on the field.

An object of the present invention is to provide a shift operation structure for an agricultural vehicle so that pressure oil is not suddenly supplied to the reverse hydraulic clutch when the shift operation is performed from a forward shift position to a reverse shift position.

[Means for solving problems]

A feature of the present invention is that, in the above-mentioned speed change operation structure for an agricultural vehicle, an actuator is provided which drains oil when the control valve is in the forward position and is supplied with pressure oil from the control valve in parallel with the reverse hydraulic clutch when the control valve is in the reverse position. The functions and effects are as follows.

[For production]

If an actuator like the one described above is installed, when the control valve is switched from the forward position to the reverse position, pressure oil will not be supplied only to the reverse hydraulic clutch, but will be drained in the forward position. Pressure oil is simultaneously supplied from the control valve to both the actuator and the reverse hydraulic clutch. As a result, pressure oil is supplied to the reverse hydraulic clutch more slowly than in the conventional structure, and the reverse hydraulic clutch does not suddenly become engaged.

〔Effect of the invention〕

As explained above, when the control valve is switched from the forward position to the reverse position, pressure oil is supplied from the forward hydraulic clutch to the reverse hydraulic clutch more slowly than in the conventional structure. The shock has been softened, improving the running stability of agricultural vehicles.

〔Example〕

EMBODIMENT OF THE INVENTION Hereinafter, an agricultural combine harvester which is one of the embodiments of the present invention will be described based on the drawings.

As shown in Figure 3, a pair of left and right crawler traveling devices (1
), (1) is equipped with a threshing device (2) in the center of the vehicle body (3), and a pulling device (4) and a reaping device (
5) A combine harvester is constructed by connecting the reaping pre-processing section (7), which is composed of the reaped husk culm conveying device (6), in a vertically movable manner.

Next, the traveling transmission system of the combine harvester will be explained in detail.
As shown in the figure, the engine (
The power from 8) is branched into a transmission system for the threshing device (2) and a transmission system for driving the traveling and reaping surface processing sections. The latter branched power is transmitted to the input shaft (1) of the traveling transmission case (9).
0) through a tension clutch (11), and is further branched into a traveling system and a reaping section transmission system.

A part of the power from the input shaft (10) is taken out to the PTO shaft (13) via a two-speed high/low gear transmission (12), and from there a tension clutch-type reaping latch (14).
) to the input shaft (15) of the reaping pre-processing section (7). In addition, a part of the power of the input shaft (10) is transmitted to an auxiliary transmission (16) with two high and low gears, a main transmission (17) with three forward gears and one reverse gear, and a steering clutch (18).
, (18) to the left and right axles (19), (19
).

The main transmission (17) includes a multi-mechanical hydraulic clutch (20a) in the transmission system of the school gear pairs forming each gear stage.

(20b), (20c), and (20d) are incorporated, respectively, and these hydraulic clutches (20a) and (20b) are assembled.
... is configured as a hydraulically operated traveling transmission that selectively supplies pressure oil to perform transmission at a desired gear position. Also, like the main transmission (17), the auxiliary transmission (16) also has a high speed
Two hydraulic clutches (21a
).

(21b) is a hydraulically operated type.

Next, both transmissions"':!r (16), (17
) The hydraulic path for supplying pressure oil to the hydraulic clutches (20) and (21) of the engine (8) is as shown in Fig. 1. The oil is supplied to the main control valve (2) which selectively supplies pressure oil to the hydraulic clutch (20) of the main transmission (17).
3). This main control valve (23) is connected to the first control section (
23a) and the second control section (23b) at the same time, and the re-control section (23a), (2
3b) to the (F+), (Fz), (F3) and (R) positions to move forward to 1st, 2nd, 3rd,
Reverse 1st speed hydraulic clutches (20a), (20b)
, (20c), and (20d).

From the first control part (23a) to the second control part (23a) of the main control valve (23)
A branch path (
24) and (25), one of them (24)
the hydraulic clutch (21a) of the auxiliary transmission (16),
(21b), and the other branch path (25) is connected to a modulating relief valve (27).
) is switched from the neutral position (N) to another position to prevent the clutch operating pressure from rising rapidly, thereby alleviating the shock at the time of starting.

Further, the first control section (23a) is provided with a path (28) for supplying pressure oil for operation to the reaping latch (14) that transmits power to the pre-reaping processing section (7) of the combine. The reaping latch (14) is biased toward the clutch engagement side by a spring (29). Said path (28) is connected to an actuator (30) for cutting and operating the cutting latch (14).
- connected to a single acting hydraulic cylinder as an example.

Further, when the single-acting hydraulic cylinder (30) is in the forward position (PI), (F2), or (F3), oil is drained, and when it is in the neutral position (N), pressure oil is supplied, and when it is in the reverse position (R). Each position of the first control section (23a) is configured so that it is simultaneously supplied with pressure oil in parallel with the reverse hydraulic clutch (20d) of the main transmission (17). Therefore, the main control valve (23) is in the forward position (F
, ), (FZ), (pi), the single-acting hydraulic cylinder (30) is drained of oil and the reaping latch (14)
is in the entered state. From this state, the main control valve (23
) is switched to the reverse position (R), pressure oil is also supplied to the single-acting hydraulic cylinder (30) from the first control section (23a) of the main control valve (23), and the reaping latch (14
) is being operated to disengage the reverse hydraulic clutch (20d).
is engaged and operated, and the reverse hydraulic clutch (2
0d) does not suddenly enter the state, the shock at that time is suppressed, and the changeover from forward to reverse is performed smoothly.

[Brief explanation of drawings]

The drawings show an embodiment of the transmission operation structure for an agricultural vehicle according to the present invention, in which Fig. 1 is a hydraulic supply system diagram, Fig. 2 is a diagram showing the transmission and power transmission path, and Fig. 3 is an overall side view of the combine harvester. It is a diagram. (14)...Working clutch, (17)...
...Transmission device, (20) ...Hydraulic clutch,
(20d)...Hydraulic clutch for reverse, (23
)... Control valve, (30)... Actuator.

Claims (2)

[Claims] (1) Equipped with a hydraulically operated driving transmission (17) that performs gear shifting by selectively operating a plurality of hydraulic clutches (20) for shifting gears by supplying pressure oil from a control valve (23). This is a speed change operation structure for a certain agricultural vehicle, in which oil is drained when the control valve (23) is in the forward position, and the control valve (23) is connected in parallel with the reverse hydraulic clutch (20d) when the control valve (23) is in the reverse position.
A gear shift operation structure for an agricultural vehicle, which is equipped with an actuator (30) supplied with pressure oil. (2) The shift operation structure for an agricultural vehicle according to claim 1, wherein the actuator (30) is for operating a clutch (14) for a working device that is biased toward the clutch engagement side. .